1. Field of the Invention
This invention is generally directed to supports used in conjunction with paper or fiber coffee and similar beverage filters and more specifically the filter paper stabilizing rings which are selectively receivable within a coffee or similar filter in such a manner as to maintain the sides of the filter in their proper upright orientation without pinching or collapsing the side walls thereof. The filter rings also are constructed so as to not interfere with the lower portion of the filter wherein coffee grounds are placed and to not interfere with the slideable engagement between the filter tray and a coffee maker.
2. History of the Art
In conventional automatic drip type coffee makers, coffee grounds are maintained in an open bowl shaped paper or fiber filter which is selectively supported in a filter tray which tray is slideably retained by the automatic coffee maker. In use, hot water from the coffee maker passes into the coffee grounds carried within the filter paper and passes through an opening provided in the lower central portion of the filter support tray. One major problem that exists with the use of automatic drip coffee makers is that, frequently, the filter paper will become bent or collapsed as the filter support tray is slidingly urged into proper position in the coffee maker. Coffee makers are made with little clearance between the upper edges of the filter support tray and the water heating chambers. This being the case, as the trays are placed in position, the filter paper which often extends slightly above the upper edges of the support tray will engage a portion of the coffee maker housing and be bent over thereby blocking the flow of water directly into the coffee grounds which are placed within the filter. When this condition occurs, the hot water will be partially drained along the edges of the filter paper and bypass the coffee grounds.
In an effort to cause paper filters to retain their predesignated shaped within the trays of drip type coffee makers, manufacturers have recommended that consumers utilize filter papers having corrugated or pleated side walls. The corrugations are provided in order that the filter paper retain its natural shape in varying sizes of support trays as well as to provide a spring-like function to urge the filter out into its normally open configuration in the event it is slightly deformed when the filter support tray is being placed within the coffee maker. Unfortunately, such corrugated filters are also subject to being collapsed as the coffee filter tray is placed within the coffee maker resulting in an unsatisfactory brewing cycle as the flow of water is directed in a path which substantially bypasses the coffee grounds carried in the filter.
In older non-automatic type drip coffee makers, filters were frequently maintained within the coffee pot or brewing container by means of interlocking support rings which would engage the upper portion of the filter and lock it in fixed relation with respect to the coffee pot. Such devices were utilized to suspend a filter within the pot and are not compatible with the conventional type support trays which are utilized with today's automatic drip coffee makers. One of the benefits of the conventional drip type coffee makers utilized today is their operating convenience. The ability to use a disposable coffee retaining filter in a support tray allows coffee grounds to be easily placed within the coffee maker and quickly and cleanly disposed of once a brewing cycle is completed with only slight rinsing of the tray being required after a brewing cycle. In the older types of filter locking or engaging rings, the multi-component filter retainers not only required additional handling by the consumer but the multi-component parts thereof required that the parts be disassembled in order to dispose of used coffee grounds and filters. Therefore, such multiple filter retaining mechanisms are not appropriate for use in today's automatic drip type coffee maker equipment. In addition, prior art filter interlocking support rings for suspending coffee filters with respect to a coffee pot have been designed without consideration of the need to insure that any coffee filter supporting apparatus does not interfere with the proper engagement of a filter support tray and a coffee maker housing and does not adversely affect the shape of the filter element. Many prior art filter supports included vertically extending side wall portions which were elevated with respect to the upper edges of the filter and therefore could not be utilized in conventional drip type coffee makers used today.
Other, more recent, prior art devices which have been designed to retain the upper edges of coffee filters in proper position within a support tray have utilized fixed locking devices carried by the support tray. Such devices may include pivotable arms or clamps which swing from the upper edge of the tray into overlapping engagement with the upper edge of the filter in order to maintain the filter against the side of the tray. Such devices not only add to the manufacturing costs of the trays but are also not totally adequate in that they do not continuously engage the entire circumference of a filter.
Some examples of prior art coffee filter retainers include U.S. Design Pat. No. 217,381 to Douglas, U.S. Pat. Nos. 232,817 to Harrison; 1,168,544 to Newlin; 3,388,804 to Hester and 4,176,588 to Baron.